Orthotropy and plagiotropy

"Orthotropy (Fig. 14A; Frank, 1868; Koriba, 1958) refers to axes whose general orientation is vertical and whose symmetry is radial, with leaves in a spiral, opposite or verticillate disposition, and associated lateral branches arranged in all spatial directions. Plagiotropic axes (Fig. 14B; Frank, 1868; Koriba, 1958) have a general horizontal to slanted orientation and a bilateral symmetry owing to leaves (distichous phyllotaxis) and branches being generally arranged in one plane."